Add custom and builtin place holders replacement functionality

[PrzemyslawKlys]

This PR adds:

• Ability to define custom place holders:

New-ConfigurationPlaceHolder -Find '{CustomName1}' -Replace 'SpecialCase1'
New-ConfigurationPlaceHolder -Find '{CustomName2}' -Replace 'SpecialCase2'

Or

New-ConfigurationPlaceHolder -CustomReplacement @(
        @{ Find = '{CustomName}'; Replace = 'SpecialCase' }
        @{ Find = '{CustomVersion}'; Replace = '1.0.0' }
)

• It also has builtin place holders replacement:

Current known replacements are:

<ModuleName> / {ModuleName} - the name of the module i.e PSPublishModule
<ModuleVersion> / {ModuleVersion} - the version of the module i.e 1.0.0
<ModuleVersionWithPreRelease> / {ModuleVersionWithPreRelease} - the version of the module with pre-release tag i.e 1.0.0-Preview1
<TagModuleVersionWithPreRelease> / {TagModuleVersionWithPreRelease} - the version of the module with pre-release tag i.e v1.0.0-Preview1
<TagName> / {TagName} - the name of the tag - i.e. v1.0.0

That means it's not necessary to define custom code with that, just use known replacements

[SamErde]

Thanks, Przemek!